For example, a known piezoelectric actuator includes three piezoelectric layers stacked one above another. The piezoelectric actuator further includes first conductors, second conductors, and individual electrodes. The first conductors are disposed between the middle piezoelectric layer and the lowest piezoelectric layer. The second conductors are disposed between the top piezoelectric layer and the middle piezoelectric layer. The individual electrodes are disposed on an upper surface of the top piezoelectric layer. One each of the first conductors, the second conductors, and the individual electrodes are provided for each of a plurality of pressure chambers. Each of the first conductors overlaps, in a top-bottom direction, confronting end portions of adjacent pressure chambers in a sheet feeding direction. The first conductors are connected to each other by a first common wiring and are maintained at a ground potential. Each of the second conductors overlaps a central portion of a corresponding one of the pressure chambers in the top-bottom direction. The second conductors are connected to each other by a second common wiring and are maintained at a predetermined driving potential. The individual electrodes are provided for the pressure chambers correspondingly while each of the individual electrodes extends substantially throughout a length and width of a corresponding pressure chamber. Each of the individual electrodes overlaps, in the top-bottom direction, a corresponding one of the first conductors and a corresponding one of the second conductors. Each of the individual electrodes may be applied with one of the ground potential and the driving potential.